In recent years, with the rapid development of wireless communication technologies, personal data cards have been popularized and widely used. Such a data cards in use is always connected to a user terminal (e.g., a notebook or a netbook) through a data adapter (USB plug), and then a network connection is carried out. However, as material of the user terminal is generally metallic, when the data card is close to such material, antennas of the data card may be affected by metallic parts, thereby resulting in a decrease of radiation efficiency of the antenna and a distortion of a radiation pattern of the antenna, and finally affecting users' use.
In order to improve network speed of wireless terminal products used by the users, at present, antenna diversity techniques are generally adopted. In this case, two antennas, which are respectively a main antenna and a diversity antenna, are arranged in one data card. Utilizing the diversity antenna has a benefit that the download speed of the data card can be improved. However, as a certain space is required to arrange the diversity antenna, the size of the current data card is generally large. Therefore, the cost of the data card is increased while the appearance is not attractive.